We are developing a magneto-nano sensor protein chip and a multiplex magnetic sorter based on magnetic[unreadable] nanoparticles that allow rapid conversion of discrete biomolecule binding events into electrical signals.[unreadable] These nanotechnologies can detect target molecules down to the single molecule level in less than an hour.[unreadable] Such sensitivity and detection speed are unavailable or impractical with current technologies. The two main[unreadable] components of this project, a magneto-nano sensor chip and a nanoparticle-based magnetic sorter, can[unreadable] operate independently or in conjunction. The maqneto-nano sensor chip will recognize and quantitate protein[unreadable] tumor markers and relevant protein profiles in mouse and human serum samples with unprecedented[unreadable] sensitivity and specificity. These magneto-nano sensors function by exhibiting significant resistance changes[unreadable] which are induced solely by external magnetic fields and are therefore insensitive to solution conditions such[unreadable] as buffers, pH or ionic strength. Biological sensing is accomplished by affinity labeling both the sensor[unreadable] surface and magnetic nanoparticles to simultaneously attach to distinct domains of specifically targeted[unreadable] biological molecules. The magneto-nano sensor then detects the attachment of the biomolecules through the[unreadable] magnetic field induced by the magnetic nanoparticles. For sufficiently small sensors and appropriate[unreadable] magnetic nanoparticle tags, affinity bonding due to a single, specific molecule can be detected as a simple[unreadable] change in the sensor electrical resistance so that expensive excitation sources or remote sensors are not[unreadable] required. The magnetic sorter will rapidly segregate biomolecules. based upon the tunable magnetic[unreadable] properties of the magnetic nanoparticles which bind them, by causing them to deflect at different speeds[unreadable] under a given magnetic field and gradient. In particular, we will be extending technologies to capture and[unreadable] characterize circulating tumor cells from mouse and human serum samples and subsequently analyze the[unreadable] cell lysate for monitoring cancer therapy.[unreadable] Relevance to public health: The magneto-nano sensor protein chips and multiplex magnetic sorter[unreadable] developed in this project can ultimately be used by cancer biologists as well as clinical oncologists to rapidly[unreadable] follow numerous proteins in clinical samples in an automated and high throughput fashion. By essentially[unreadable] applying patient serum or tissue samples to the magneto-nano sensor chip, one can readily ascertain the[unreadable] presence or absence of a large number of tumor markers. Additionally, the multiplex magnetic sorter can[unreadable] perform high throughput enrichment of circulating tumor targets or depletion of impurities, improving complex[unreadable] proteomic analysis that currently suffers from poor signal-to-noise ratio.[unreadable]